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Electrokinetic‐driven microfluidic system in poly(dimethylsiloxane) for mass spectrometry detection integrating sample injection, capillary electrophoresis, and electrospray emitter on‐chip
Author(s) -
Thorslund Sara,
Lindberg Peter,
Andrén Per E.,
Nikolajeff Fredrik,
Bergquist Jonas
Publication year - 2005
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200500338
Subject(s) - electrospray , electrokinetic phenomena , microfluidics , analyte , capillary electrophoresis , chromatography , electrophoresis , analytical chemistry (journal) , mass spectrometry , capillary action , materials science , common emitter , chemistry , nanotechnology , optoelectronics , composite material
A novel microsystem device in poly(dimethylsiloxane) (PDMS) for MS detection is presented. The microchip integrates sample injection, capillary electrophoretic separation, and electrospray emitter in a single substrate, and all modules are fabricated in the PDMS bulk material. The injection and separation flow is driven electrokinetically and the total amount of external equipment needed consists of a three‐channel high‐voltage power supply. The instant switching between sample injection and separation is performed through a series of low‐cost relays, limiting the separation field strength to a maximum of 270 V/cm. We show that this set‐up is sufficient to accomplish electrospray MS analysis and, to a moderate extent, microchip separation of standard peptides. A new method of instant in‐channel oxidation makes it possible to overcome the problem of irreversibly bonded PDMS channels that have recovered their hydrophobic properties over time. The fast method turns the channel surfaces hydrophilic and less prone to nonspecific analyte adsorption, yielding better separation efficiencies and higher apparent peptide mobilities.